noun

• (ellipsis or nominalization) The person or thing in the fifth position.
• (ellipsis or nominalization) The person or thing in the fifth position.
• (US) A quantity of liquor equal to one-fifth of an American gallon, or, more commonly, 750 milliliters (that is, three quarters of a liter).
• (music) The musical interval between one note and another five scale degrees higher (the fifth note in a scale)
  "Now I've heard there was a secret chord / That David played, and it pleased the Lord / But you don't really care for music, do ya? / It goes like this, the fourth, the fifth"

verb

• (music) To sing in the fifth voice in a polyphonic melody.
  "Another extension of strict organum is 'fifthing'. Fifthing is a note-against- note method of creating a two-part texture by improvising a second voice over the given tune, starting and ending each musical phrase at the octave and proceeding mainly in fifths above the tune at others times."
• (transitive, informal) To support something fifth, after four others have already done so.
  "Though seconding (or fifthing) the praise for “BoJack Horseman” and “In Treatment,” I think I’ll use the majority of my space to discuss “You’re the Worst.”"
• (transitive, nonstandard) To divide by five.
  "3/5 has been through fifthing. 2/3 has been through thirding. Therefore, 3/5 now needs thirding and 2/3 needs fifthing"

name

• (chiefly US, informal, with the) The Fifth Amendment.
• (chiefly US, informal, with the, by extension) The right not to give self-incriminating testimony.
• (chiefly US) Fifth Avenue.
  "[…] besides marrying Nate Archibald and living happily every after in the ivy-covered brick town house just off Fifth that she already had picked out"
• (chiefly US) Fifth Street.